An important thing to understand about your inner junkie is that it’s very much like a spoiled child: it will do its best to make your life miserable unless you give it what it wants.
So, like any parent, you have to learn to say “No.” Of course, your inner junkie will throw a temper tantrum when you do: it will scream, it will stomp its feet, it will cry, it will pout, it will do whatever it thinks will push you into giving in and saying yes.
But you have to be the adult: tell it “No” and mean it. Send it to bed without its supper. Keep telling it “No” and eventually it will quiet down and go to sleep.
More on this as we go on.
(If you're feeling a bit lost, it may be helpful to go back to the first post and follow along in order.)